In this talk, a review of the information that large galaxy surveys can bring about cosmological parameters will be presented. I will describe the present and near future constraints coming from current galaxy surveys. I will review also the future projects that are proposed or in construction, and their expected sensitivities, mainly to the dark side of the universe, dark matter and dark energy.
Neutrinoless double beta decay, lepton number violating collider processes and the Baryon Asymmetry of the Universe (BAU) are intimately related. In particular lepton number violating processes at low energies in combination with sphaleron transitions will typically erase any pre-existing baryon asymmetry of the Universe. In this contribution we briefly review the tight connection between...
In this work we present a new computation of the lepton flavor violating (LFV) Higgs boson decays within the context of low-scale seesaw models, concretely the inverse seesaw model with three $\nu_R$ and three extra singlets $X$. The novelty of our computation is that it uses the mass insertion approximation (MIA) which works with the electroweak interaction states. This method also allows us...
A central theme in string cosmology in recent years has been the construction of realistic large field inflationary models through axions. In this talk we will discuss a set-up with both closed and open string axions in Type IIA string theory in which strong dynamical effects determine the inflaton candidate. The interplay of Nambu-Jona-Lasinio type interactions, gauge instantons and chiral...
Combining experimental data from the LHC, low-energy precision observables, flavor measurements and astrophysical data, we analyze various incarnations of Supersymmetry (SUSY). This work is done within the MasterCode framework. We find that simple SUSY models are in agreement with all experimental data. We obtain predictions where the LHC has the best chances to find SUSY and where the direct...
We investigate multi-lepton signals produced by ElectroWeakino (EWino)
decays in the MSSM and the TMSSM scenarios with sfermions, gluinos and non Standard
Model Higgses at the TeV scale, being the Bino electroweak-scale dark matter. We recast
the present LHC constraints on EWinos for these models and we find that wide MSSM and
TMSSM parameter regions prove to be allowed. We forecast the number...
The baryon asymmetry and dark matter in the Universe can be explained just by introducing right-handed neutrinos with masses well below the Fermi scale. For the masses of the order of GeV scale baryogenesis via neutrino oscillations works as a mechanism to generate the baryon asymmetry. We derived kinetic equations of the baryogenesis accounting for fermion number violating effects missed so...
We develop a new class of supergravity cosmological models where inflation is induced by terms in the K\"ahler potential which mix a nilpotent superfield $S$ with a chiral sector $\Phi$. As the new terms are non-(anti)holomorphic, and hence cannot be removed by a K\"ahler transformation, these models are intrinsically K\"ahler potential driven. Such terms could arise for example due to a...
Most information about cosmological parameters and the inflationary universe comes from the CMB, however with the advent of galaxy surveys such as the DES and Euclid further constraints can be obtained from LSS. The gravitational collapse of matter is a complex non-linear process, and is typically modelled numerically with N-body codes. Since N-body codes are expensive to run many have...
I will discuss the Zee model, a radiative neutrino mass model with possible large lepton flavor violating Higgs (HLFV) decays, in particular $h\rightarrow \tau \mu$. In the first part I will analyse the effective operators responsible for HLFV and their tree level UV completions, based on arXiv:1605.06091. By imposing constraints from charged lepton flavour violating observables, like $\tau...
Inflation provides a dynamical mechanism to seed density fluctuations that eventually collapse to form all of the structure in the observable universe. However, microphysical theories of inflation often predict that on scales much larger than our present horizon, the universe may be extremely inhomogeneous.
One possible source of such ultra-large scale structure (ULSS) is from the initial...
My talk is devoted to superstring cosmology and moduli stabilization, and is based on arXiv:1607.05293 (published in JHEP), and 1703.08993 (submitted to PTEP). We search for dS vacua and slow roll inflation in a class of flux compactifications of type IIA strings on rigid Calabi-Yau manifolds with local N=2 supersymmetry in four spacetime dimensions. These theories represent a nice theoretical...
Many supersymmetry models feature gauginos and also leptons with masses less than a few hundred GeV. These can give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk presents results from searches for gaugino and slepton pair production in final states with leptons, and were performed with pp collisions at a...
I will present a simple extension of the Standard Model which adds a new scale at 10^11 GeV, solving the strong CP problem with an axion and the smallness of neutrino masses via a variant of the see-saw mechanism. This leads to a dark matter candidate (the axion), and explanation of the matter/anti-matter asymmetry of the Universe (through leptogenesis) and the identity of the inflaton. The...
We present the minimal purely fermionic model of EWBG. A strong first order phase transition is obtained from fermion-induced radiative corrections on the Higgs potential, while the baryon asymmetry is obtained from asymmetric scattering of the same set of fermions on the bubble wall. The model introduces no additional tuning below the TeV scale: all new fields are stabilized at the...
The Planck data on the CMB power spectrum marginally support pronounced deviations from scale invariance at several multipole ranges. We examine the implications of such features for the scalar bispectrum and the tensor power spectrum providing several concistency relations and templates while highlighting the power of joint analysis of spectra in search for features.
I will review recent work on a supersymmetric trinification model, where the standard trinification gauge group $[ \mathrm{SU}(3)_{\mathrm{L}} \times \mathrm{SU}(3)_{\mathrm{R}} \times \mathrm{SU}(3)_{\mathrm{C}}] \times \mathbb{Z}_3 \subset \mathrm{E}_6$ is supplemented by a global $\mathrm{SU}(3)_{\mathrm{F}}$ family symmetry. The chiral super field content of the model is taken from the...
I will discuss a simple extension of the SM with just an additional scalar singlet coupling to the Higgs. My main focus will be the possible probes of electroweak baryogenesis in this model including collider searches gravitational wave detection and direct dark matter detection experiments. I will show there are regions in the parameter space where observation of gravitational waves is the...
.Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk summarises recent ATLAS results on inclusive searches for supersymmetric squarks and gluinos, including third generation squarks produced in the decay of gluinos. The searches involve final states containing jets, missing transverse momentum...
In this talk I will start by studying some general aspects of String Theory compactifications to four dimensions, focusing on the the constraints to obtain 4 dimensional de Sitter vacua. These microscopic constraints will then be applied to some existing mechanisms to uplift the cosmological constant, that will allow us to understand the mechanisms and their limitations better.
We consider an isolated electroweak monopole solution within the Standard Model with a
non-linear Born-Infeld extension of the hypercharge gauge field. Monopole (and dyon) solutions
in such an extension are regular and their masses are predicted to be proportional
to the Born-Infeld mass parameter. We argue that cosmological production of electroweak
monopoles in a narrow mass range may delay...
Cosmological correlation functions encode the spectrum of particles during inflation, in analogy to scattering amplitudes in colliders. In this talk, I will discuss the imprints of massive particles with arbitrary spin on cosmological correlators. The spinning case is particularly interesting because the detection of massive higher-spin particles would be strongly indicative of a stringy...
We explore the phenomenological constraints of models with non-holomorphic soft SUSY breaking terms in a beyond the MSSM scenario having identical particle content. The model referred as NHSSM shows various promising features like the possibility of a strong reduction in electroweak fine-tuning even for a scenario of a heavy higgsino type of LSP, a fact that is unavailable in pMSSM models. The...
The large set of proton-proton collision data recorded in 2016 at a centre-of-mass energy of 13 TeV is the basis for first results on electroweak production of supersymmetric particles in LHC Run 2. CMS results on the production of chargino / neutralino pairs are presented based on the analysis of final states with one or more leptons and interpreted under several assumptions for the decay...
Exclusion of several classes of models due to LHC and astroparticle data has revived interest in grand unification. We consider SO(10) unified models with D-parity due to their success in incorporating light neutrino masses. We study various patterns of symmetry and supersymmetry breaking therein. Formation of topological defects in these models can alter the nature of phase transitions,...
We discuss the possible realizations of $\alpha$-attractor in Maximal supersymmetric theory/string theory/M-theory. The $\alpha$-attractor is realized with the Kahler potential $K=-3\alpha\log (T+\bar{T})$, which describes hyperbolic geometry. The tensor-to-scalar ratio $r$ in this model is proportional to $\alpha$. It is known that the 4-dimesional supersymmetric truncation of maximal...
This talk is based on the vacuum energy sequestering scenario which is an approach to tackling cosmological constant problem via global modifications of gravity. We will discuss the core issue with the cosmological constant, namely, radiative instability and show how in the vacuum energy sequestering proposal the loop corrections decouple from the gravitational field equations order by order...
Primordial magnetic fields (PMFs) can be an important ingredient in the early and even the present Universe, which might explain the present magnetic fields in the galaxies and intergalactic magnetic fields suggested by blazar observations. We discuss the production of axion-like particles (ALPs) through the photon-axion conversion through the PMFs. We identify the conditions in which the ALPs...
We examine in detail the current LHC coverage of signatures arising from the R-Parity-violating Minimal Supersymmetric Standard Model. We take into account all experimental analyses for prompt signatures within this context, both explicit searches for RPV signals as well as other analyses containing applicable experimental signatures. These are contrasted with well-motivated phenomenological...
Axion monodromy models can always be described in terms of an axion coupled to 3-form gauge fields with non-canonical kinetic terms. The presence of the saxions parametrising the kinetic metrics of the 3-form fields leads to backreaction effects in the inflationary dynamics. We analyse
the case in which saxions backreact on the Kähler metric of the inflaton leading to a logarithmic scaling of...
The Higgsino is the most promising candidate for the dark matter.
The almost pure Higgsino, however, is known to be a very challenging target at the LHC.
I will show that improvement of tracking technique of disappearing tracks can significantly increase the sensitivity for the Higgsino.
I will also discuss a future 33 TeV collider can probe the 1 TeV Higgsino, which is the most interesting...
Primordial Black Holes (PBH) arise naturally from high peaks in the curvature power spectrum of near-inflection-point single-field inflation, and could constitute today the dominant component of the dark matter in the universe. In this talk we explore the possibility that a broad spectrum of PBH is formed in models of Critical Higgs Inflation (CHI), where the quasi-inflection point is related...
We study dark matter physics in the Minimal Supersymmetric Standard Model
with non-universal gaugino masses at the unification scale.
In this scenario, the specific ratio of wino and gluino masses
realizes the electro-weak scale naturally and achieve the 125 GeV Higgs mass.
Then, relatively light higgsinos are predicted
and the neutral component is a good dark matter candidate.
The...
A prediction of the standard LCDM cosmological model, also confirmed by N-body cosmological simulations, is that dark matter (DM) halos are teeming with numerous self-bound substructure, or subhalos. The precise properties of these subhalos represent important probes of the underlying cosmological model. Subhalos may also play a key role on the search for DM via its annihilation products, as...
According to the Standard Model of Cosmology, about 25% of the content of the universe is composed of dark matter. From a theoretical point of view, there are many possible alternatives to explain its origin and composition, ranging from ultralight axions to supermassive black holes. However, despite many experimental efforts, the nature of dark matter is still obscure. One interesting...
The status of most recent measurements of the Standard Model Higgs boson production and properties are presented in this talk. The studies are based on data recorded by the CMS experiment during the 2016 and include an overview of the results of bosonic and fermionic Higgs boson decays, with a focus on the Higgs boson produced in the association to top quark pair and production with single top quark.
The electric Weak Gravity Conjecture demands that axions with large decay constant $f$ couple to light instantons. The resulting large instantonic corrections pose problems for natural inflation. We explore an alternative argument based on the magnetic Weak Gravity Conjecture for axions, which we try to make more precise. Roughly speaking, it demands that the minimally charged string coupled...
We consider extended scalar sectors of the Standard Model as ultraviolet–complete motivations for studying the effective Higgs self–interaction operators of the Standard Model effective field theory. We investigate all motivated heavy scalar models which generate the dimension–6 effective operator, |H|^6, at tree level and proceed to identify the full set of tree–level dimension–six operators...
The XENON100 experiment is designed to search for dark matter in the form of weakly interacting massive particles (WIMPs) by detecting WIMP-induced nuclear recoils (NRs) with a liquid xenon (LXe) time projection chamber. The modulation of the low energy (low-E), (2–6) keV event rate in the DAMA/LIBRA experiment is currently the only long-standing claim for a positive dark matter detection. One...
We consider formation of primordial black holes (PBHs) in multi-field inflation models ( double inflation or axion curvaton model ) and discuss the possibility that produced PBHs account for the observed gravitational events by LIGO or all dark matter of the universe. We point out that the current pulsar timing array (PTA) experiments already put severe constraints on gravitational waves...
The Weak Gravity Conjecture (WGC) has recently received much attention for its potential applications to models of large field inflation. Unfortunately, generic motivations behind the WGC remain somewhat weak. In this talk, I will discuss suggestive arguments hinting at the WGC in two different contexts: extremal black holes in Einstein-Maxwell theories, and 'axionic black holes' in theories...
Triple Chern-Simons terms are a generic feature of stringy compactifications, where they are usually responsible for topological masses, or branes ending in branes. Another piece of common lore says that one should not expect exact global symmetries in quantum gravity, and in fact this is the case in every known stringy compactification. I will argue that these two seemingly disconnected...
We define a Focus Point (FP) Asymmetry, $A_{\rm FP}$, obtained by integrating the normalised transverse momentum distribution of either lepton produced in the Drell-Yan (DY) process below and above a point where a variety of popular $Z^\prime$ models all have the same magnitude.
For a given $Z^\prime$ mass the position of this FP is predictable, depending only on the collider energy and on...
Modified gravity models with screening mechanisms, such as galileons, are prime dark energy candidates but they are notoriously difficult to test. In this talk, I will discuss a new scenario for testing galileons. Black holes do not feel the galileon force and, as a consequence, the supermassive black holes in galaxies falling into clusters should be offset from the galactic centre by a...
The identification of dark matter is presently one of the greatest challenges in science, fundamental to our understanding of the Universe. Weakly Interacting Massive Particles (WIMPs) that arise naturally in several models of physics beyond the Standard Model are compelling candidates for dark matter.
The LUX-ZEPLIN (LZ) collaboration is constructing a massive dark matter detector, to be...
There exist well motivated models of particle dark matter which predominantly scatter inelas- tically off nuclei in direct detection experiments. This inelastic transition causes the dark matter to up-scatter in terrestrial experiments into an excited state up to 550 keV heavier than the dark matter itself. An inelastic transition of this size is highly suppressed by both kinematics and...
Dynamical scanning of the Higgs mass by an axion-like particle during inflation may provide a cosmological component to explaining part of the hierarchy problem. We propose a novel interplay of this cosmological relaxation mechanism with inflation, whereby the backreaction of the Higgs vacuum expectation value near the weak scale causes inflation to end. As Hubble drops, the relaxion's...
We propose a new scenario of cosmological relaxation compatible with reheating temperature higher than the electroweak scale. Cosmological relaxation is a novel solution to the hierarchy problem, which is proposed recently. However, the barrier potential, that settles the relaxion down to realize the correct electroweak scale, vanishes at high temperature where the electroweak symmetry...
The Global and Modular Beyond-the-Standard Model Inference Tool (GAMBIT)
is an open-source tool for performing global fits in generic Beyond the Standard Model theories. GAMBIT is the amalgamation of frontline scanner algorithms, advanced calculations of physical observables and likelihoods, and a flexible and powerful interface with the user and external codes. Due to the deep modularity of...
Ultralight bosonic particle is one of the dark matter and called fuzzy dark matter.
Its astrophysical properties are interesting and have been recently studied.
On the other hand, the detection method is less discussed. We propose a new method to detect them using the motions of heavenly bodies.
(This is a work in progress)
I will discuss the untrendy 2 TeV excess in the ATLAS Run 1 hadronic diboson resonance search, pointing out its faint reappearance in three subsequent analyses. On a more general ground, I will discuss the weakness of the strategies used by ATLAS and CMS in this and other new physics searches, and propose a more robust approach to detect unconventional new physics.
Semi-annihilation is a generic feature of dark matter theories stabilized by symmetries larger than a $Z_2$. It contributes to thermal freeze out, but is irrelevant for direct and collider searches. This allows semi-annihilating dark matter to avoid those limits in a natural way. We use an effective operator approach to make the first model-independent study of the associated phenomenology....
Talk shall describe the role of light fields indirectly coupled to background during preheating. In our previous study, when we considered massless background field, we proved that non-perturbative production of states associated with such fields can be sizeable due to quantum corrections. Talk will extend this study considering massive inflaton within the interacting field formalism. It helps...
I will discuss two ways in which revising the notion of time at the Big Bang will lead to testable predictions. I will then contrast these predictions against standard ΛCDM scenario, and cosmological observations. The first model, Holographic Cosmology, is based on a 3d quantum field theory without time, suggesting the possibility of nonperturbative effects on large angles (l<30) in the CMB...
The Belle II experiment is a substantial upgrade of Belle detector and will operate at the SuperKEKB energy-asymmetric $e^+e^-$ collider, which has started commissioning and is working towards its design luminosity of $8 \times 10^{35}$ cm$^{-2}$s$^{-1}$. The Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than the Belle experiment. This large data set will be...
We propose a phenomenological class of inflationary models in which the assumption of inflaton slow-roll is replaced by more general, constant-roll condition. We derive general exact solution for the inflaton potential and dynamics, and show that there exists parameter region that satisfies the latest observational constraint on the scalar spectral index and the tensor-to-scalar ratio. We...
Several anomalies in $b \to s$ transitions have been recently reported
by the LHCb collaboration. These include discrepancies with the Standard Model predictions in some angular observables and branching ratios and three intriguing hints for lepton universality violation in the $R_K$ and $R_{K^\ast}$ ratios. We study the implications of these results using a model-independent approach based on...
We find the explicit form of two-point function for the conformal spin-2 energy momentum operators on the near horizon of a near extremal Kerr black hole by variation of a proper boundary action. In this regard, we consider an appropriate boundary action for the gravitational perturbation of the Kerr black hole. We show that the variation of the boundary action with respect to the boundary...
The WIMP-paradigm tells us that a neutral particle with an EW cross-section and an electroweak-scale mass roughly explains the observed relic abundance. However, a closer look reveals that this correspondance is quantitatively not very precise since multi-TeV dark matter masses are reached for the simplest models, which is 1-2 orders of magnitude larger than the electroweak scale. But with an...
In this talk, we discuss a scenario to generate flavor violating $Z'$ interactions at one loop level, by introducing $U(1)_{\mu-\tau}$(-like) gauge symmetry, extra vectorlike quark doublets $Q'_a$ and singlet scalar $\chi$. Both $Q'_a$ and $\chi$ are charged under $U(1)_{\mu-\tau}$ and carry odd dark $Z_2$ parity. Assuming that $\chi$ is the dark matter (DM) of the universe and imposing...
We analyze two models in which primordial inflation has non-standard features. In the first model we study the evolution of a system in which the inflaton is slowed down by dissipation of energy into gauge bosons instead of the usual Hubble friction: in particular we study the conditions of the onset of such a scenario from a static field configuration, its evolution and we mention some...
The supersymmetry arises in certain theories of fermions coupled to gauge fields and gravity in a spacetime of eleven dimensions. The dynamical M-brane backgrounds have mainly been studied for the class of purely bosonic solutions only, but developments involving time-dependent supersymmetric solution have made it clear that one can get more information by asking what happens on dynamical...
We discuss the capability of next generation of Direct Detection experiments, for example XENON1T and LZ, as well as of future runs of LHC and possible future accelerators, of fully probing the WIMP paradigm. We will indeed show, in some simple relevant cases of study, that the projected sensitivities of these experiments can fully cover the parameter space corresponding to the correct DM...
A violation of the diffeomorphism (Diff) invariance generically induces an additional degree of freedom. In Horava-Lifshitz (HL) gravity, where the 4D Diff invariance is broken into the foliation preserving Diff, there appears a scalar degree of freedom in the gravity sector, Khronon, which describes the degree of freedom for the time foliation. One may naively expect that during inflation, we...
The small quark mixing, described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix in the Standard Model,
may be a clue to reveal new physics around the TeV scale.
We consider a simple scenario that extra particles in a hidden sector radiatively
mediate the flavor violation to the quark sector around the TeV scale and effectively realize the observed CKM matrix.
The lightest particle in the...
Higgsinos and Wino have strong motivations for being
Dark Matter (DM) candidates in supersymmetry, but their annihilation cross sections are quite large.
For thermal generation and a single component DM setup
the higgsinos or wino may have masses of around 1 or 2-3 TeV respectively. For such DM candidates,
a small amount of slepton coannihilation may decrease the effective DM...
We complete the renormalization program of (projectable) Horava gravity. We show that the theory is renormalizable in any space-time dimension, preserving scaling and gauge invariance of the counter-terms at any order in the loop expansion. Later, we focus on 2+1 dimensions, where we show that the renormalization group flow of the marginal couplings contains a UV fixed point leading to...
I will discuss the cosmological consequences of higher-dimensional operators respecting the asymptotic symmetries of the tree-level Higgs inflation action. The main contribution of these operators to the renormalization group enhanced potential is localized in a compact field range, whose upper limit is close to the end of inflation. The spectrum of primordial fluctuations in the so-called...
We investigate the constraints on exotic charges of standard model and dark sector fermions coming from the cancellation of gauge anomalies in simplified models of dark matter. Assuming generation-independent charges, we show that the standard coupling structures assumed in such models necessitate the existence of additional exotic fermions. These fermions cannot be arbitrarily heavy, and some...
I will propose new-type grand unified theories (GUTs) based on GUT gauge groups broken to their special subgroups as well as their regular subgroups. In the framework, to obtain the Standard Model (SM), 4D gauge anomaly cancellation restricts the minimal number of generations of the 4D SM Weyl fermions. In this talk, I will show that in an SU(16) GUT on 6D orbifold space whose GUT group is...
We study all translationally and rotationally invariant local theories involving massless spin 2 and spin 1 particles that mediate long range forces, allowing for general energy relations and violation of boost invariance. Although gauge invariance is not a priori required to describe non Lorentz invariant theories, we first establish that locality requires `soft gauge invariance'. Then by...
The putative black holes which may constitute all the dark matter are described by a Kerr metric with only two parameters, mass M and angular momentum J. There has been little discussion of J since it plays no role in the upcoming attempt at detection by microlensing. Nevertheless J does play a central role in understanding the previous lack of detection, especially of CMB distortion. We...
We revisit the non-thermal gravitino production at the (p)reheating stage after inflation. Particular attention is paid to large-field inflation models with a $\mathbb{Z}_2$ symmetry, for which the previous perturbative analysis is inapplicable; and inflation models with a stabilizer superfield, which have not been studied non-perturbatively. It is found that in single-superfield inflation...
We study moduli stabilization of F-theory compactified on an elliptically fibered Calabi-Yau fourfold arising from open mirror symmetry prescription including the brane deformation.
We focus on a particular background and utilize associated fourfold periods to determine the properties of resulting $4$D ${\cal{N}}=1$ effective theory for moduli fields. We find that the F-theory vacua has a...
Scalar fields with non-canonical kinetic terms are ubiquitous in theories of dark energy and modified gravity. This naturally raises the question of how non-perturbative effects, like domain walls and quantum tunneling, are modified in the presence of these kinetic terms. Focusing on galileons, which appear in the decoupling limit of massive gravity and DGP, I will discuss the construction and...
In models of inflation driven by an axion-like pseudoscalar field, the inflaton, a, may be coupled to the standard model hypercharge via a Chern-Simons-type interaction, L ⊃ a F F̃ . This coupling results in explosive gauge field production during inflation, which has two interesting phenomenological consequences: (1) The primordial hypermagnetic field is maximally helical and, thus,...
A unified theory of the non-Abelian gauge interactions with gravity in the framework of a discretized Kaluza-Klein theory is constructed with a modified Dirac operator and wedge product. All the couplings of chiral spinors to the non-Abelian gauge fields emerge naturally as components of the couplings of the chiral spinors to the generalized gravity together with some new interactions. In...
We expand the GUT scenarios studied in in arXiv:1511.06205 with an analysis of the Pati-Salam (PS) group. The new SUSY scenarios that can be directly compared with our previous SO(10) analysis. Regarding neutralino relic density, the PS group can fit WMAP bounds in areas where gluinos and stops can coannihilate with the neutralino. We also investigate whether the models can predict a...
The Two-Higgs-doublet model (2HDM) is one of the most studied extensions of the Standard Model. But just as the other popular "New Physics" models, it gets more and more constrained by recent experimental progress, especially by the LHC data. For all four 2HDM types with a softly broken Z2 symmetry, we present updated results of global analyses obtained with the open-source HEPfit code. We...
We show that a detectable tensor-to-scalar ratio (r≥0.001) on the CMB scale can be generated even during extremely low energy inflation which saturates the BBN bound ρ=(30MeV)^4. The source of the gravitational waves is not quantum fluctuations of graviton but those of SU(2) gauge fields, energetically supported by coupled axion fields. The curvature perturbation, the backreaction effect and...
Nature is full of examples pairings of small but massive compact objects (of linear size R) interacting with and controlling the motions of their neighbours over within a much larger surrounding domain (of size a ≫ R). For such systems familiar arguments (such as the multipole expansion) show that only a few features of the compact object are relevant to understanding motions in their larger...
Two-Higgs-doublet models (2HDM), {\em per se}, cannot predict the
values of the nonstandard scalar masses ($m_H, m_A$ and $m_+$).
However, assuming that a type-II 2HDM arises as an effective theory at
the electroweak scale from a supersymmetric ultraviolet (UV)
completion, where the quartic couplings of the 2HDM potential are
related to the gauge couplings of the Standard Model (SM), the...
A general mechanism for thermal production of dark matter (DM) via 3-to-2 scatterings, or other higher-order interactions, allows for sub-GeV dark matter and strong self-interactions that meet existing constraints but have the potential to explain mysteries with cold DM and structure formation. In such models, so-called Strongly Interacting Massive Particles (SIMPs), a correct thermal average...
Contrary to popular belief stochastic gravitational waves might exist in reach of aLIGO (in operation by about 2020). I present a scenario, based on a scalar singlet extension of the Standard Model, that generates such gravitational waves.
The observation of a Higgs-like boson with a mass near 125 GeV/c2 at the Large Hadron Collider raises a critical question of whether the new particle is in fact the SM Higgs boson. Searches for non-SM Higgs boson production and its decay modes are therefore complementary. I will report the searches for extended Higgs sectors performed with the CMS detector. I will focus on Dark Susy and NMSSM...
We study the muon g-2 and neutralino dark matter as explained by the MSSM where the squarks and 3rd generation sleptons are decoupled. Particularly, we focus on constraints from current and future dark matter experiments such as PandaX-II and LUX-2016 as well as current bounds from collider searches. Using the constraints on the MSSM from the muon g-2 and DM searches, we study constraints from...
Combining the ideas of quantum scale invariance with the absence of new particle thresholds between the Planck and the Electroweak (EW) scales leads to stability of the latter against quantum corrections. However, the large discrepancy between the scales remains unexplained. We suggest a non-perturbative mechanism of generation of the EW scale that is able to reproduce naturally this hierarchy.
We revisit the singlet-doublet dark matter model with a special emphasis on the CP violation effect on the dark matter phenomenology. The CP violation in the dark sector induces a pseudoscalar interaction of a fermionic dark matter candidate with the SM Higgs boson. The pseudoscalar interaction helps the dark matter candidate evade the strong constraints from the dark matter direct detection...
We investigate the phenomenology of Composite 2-Higgs Doublet Models (C2HDMs) of various Yukawa types based on the global symmetry breaking SO(6)→SO(4)×SO(2). The kinetic part and the Yukawa Lagrangian are constructed in terms of the pseudo Nambu-Goldstone Boson (pNGB) matrix and a 6-plet of fermions under SO(6). The scalar potential is assumed to be the same as that of the Elementary 2-Higgs...
Primordial black holes (PBHs) are one of the candidates to explain the gravitational wave (GW) signals observed by the LIGO detectors. Among several phenomena in the early Universe, cosmic inflation is a major example to generate PBHs from large primordial density perturbations. In this talk, we discuss the possibility to interpret the observed GW events as mergers of PBHs which are produced...
In quantum mechanics and quantum field theory the perturbative series usually have factorially growing coefficients, hence being non-convergent asymptotic expansions. In order to go beyond the approximation given by the optimal truncation one can Borel-resum the series but generically extra contributions (non-perturbative in the coupling) such as instantons, must be included to reproduce the...
Motivated by the possibility of enhancing dark-matter self-interaction cross-section $\sigma_{\rm self}$, we have revisited the issue of dark matter annihilation through a Breit-Wigner resonance.
For instance the resonance-enhanced early-universe annihilation cross section implies so small cross section for elastic scattering between dark matter and the Standard Model, that effects of early...
The study of the renormalization group improved effective potential of the Standard Model has revealed the existence of a local maximum at field strengths of the order of 10^10 GeV. If the Standard Model is valid for very high energy scales, then the possibility of the production of cosmological domain walls in the early Universe occurs.
We investigated the dynamics of networks of domain...
I will describe a modified version of the dimensional regularization of a classically scale invariant theory, motivated by the requirement to preserve scale invariance at the quantum level. The role of the subtraction scale $\mu$ is played be a dynamic scalar field. This field is assumed to have non-zero VEV thus triggering spontaneous breakdown of scale symmetry which in turn triggers EWSB....
I will discuss the structure of the loop corrections in the case of the non-linear EW effective theory and compare it with the low-energy contributions from the exchange of heavy resonances. The convenience of using either the non-linear HEFT or the linear SMEFT will depend on the interplay of the scales that control these two types of contributions.
There are results that suggest a connection between gauged maximal supergravities and asymmetric toroidal orbifolds. By looking at several examples we argue that a similar relationship exists between 4D N=2 gauged supergravities and asymmetric Gepner models. Going further we conjecture that the asymmetric CFTs we construct are the fully backreacted string uplifts of N=1 Minkowski vacua in a...
I will discuss symmetric and asymmetric dark matter with long-range interactions, in particular dark matter coupled to a light vector or scalar force mediator. Accurate determination of the relic abundance requires inclusion of Sommerfeld enhancement and consideration of bound state formation. Due to the Sommerfeld enhancement, highly asymmetric dark matter with long-range interactions can...
The origin of the matter / antimatter asymmetry is one of the most persistent and challenging problems in the study of the early universe. In this talk I will describe how the baryon asymmetry may have arisen from the decaying helicity of a primordial (hyper-)magnetic field without further need for beyond-the-SM particles or interactions. The relic baryon asymmetry is shown to depend...
We revisit the decoupling effects associated with heavy particles in the renormalization group running of the vacuum energy in a mass-dependent renormalization scheme. We find the running of the vacuum energy stemming from the Higgs condensate in the entire energy range and show that it behaves as expected from the simple dimensional arguments meaning that it exhibits the quadratic sensitivity...
